code: def trace_graph(f, x):
      start_node = GraphNode.new_root(x)
      _, node = trace(start_node, f, x)
      return node
  
file_path: autograd/examples/dot_graph.py
imports: from __future__ import print_function
  import autograd.numpy
  from autograd.tracer import trace, Node
  from autograd import grad
label_desc: Use image node_id 1 for calling a global function with example usage: trace_graph(f, x) and returns: node